Romney was the choice of 27 percent of those polled, followed by Ron Paul at 11.5 percent.

And Bachmann, who won the party's pay-to-play straw poll in August? The university's surveyors — students and faculty from the university's political science department — found that she was the choice of just 3.9 percent of likely GOP caucus goers questioned in the poll.

That puts her behind former House Speaker Newt Gingrich (7.7 percent), and Texas Gov. Rick Perry (5.9 percent), and just ahead of former Pennsylvania Sen. Rick Santorum (3.1 percent.)

The poll was conducted Oct. 12 through 19, mostly before his hammering in the GOP debate on Oct. 18, as well as controversial statements he made about his position on abortion. Other Iowa polls also show Cain leading in the state.

"Right now, the race in Iowa appears to be shaping up as a two-person contest, though it will be interesting to see if Cain can stay on top, since similar surges by Bachmann and Perry ran out of steam," Hawkeye Poll adviser Fred Boehmke, associate professor of political science in the UI College of Liberal Arts and Sciences, said in a statement.

Of the 778 people surveyed, 181 said they were "somewhat" or "very" likely to participate in the 2012 Republican caucus. The margin of error for that group, according to poll officials, is plus or minus 7.4 percent.